簡單開發k8s多集群後臺
阿新 • • 發佈：2018-08-08
return ivr divide ear ots ole plugins box jquer 詳細的說明如何利用kubernetes api創建一個支持多集群的k8s後臺，這裏主要實現調用kubernetes api獲取查看service服務，pod服務。下一篇再說明如果操作一個service，以及註入容器console
- 相關的組件
- Django (2.0.7)
- kubernetes (6.0.0)
- Django Rest Framework (3.8.2)
- Bootstrap 3.3.7
- Jquery 2.1.1
- pace 頁面異步加載插件
- 新建一個基於django的k8s項目,命名為k8s_web_console
- 增加一個cluster應用
python manage.py startapp cluster
- 添加 Django Rest Framework
- 使用rest框架是方便做前後端分離，如果你是個全棧工程師，建議做前後端分離，這樣方便維護。但這裏為了入門快速方便，如果還要加一個node.js開發，比較麻煩，所以暫時保留這種可能，但還是用django的template方式開發。
pip install djangorestframework- 在setting.py中加入rest框架
INSTALLED_APPS = [ ‘django.contrib.admin‘, ‘django.contrib.auth‘, ‘django.contrib.contenttypes‘, ‘django.contrib.sessions‘, ‘django.contrib.messages‘, ‘django.contrib.staticfiles‘, ‘rest_framework‘, ‘cluster‘, ]
- 創建數據庫以及數據表
python manage.py makemigrations
python manage.py migrate-
打開cluster應用下的models.py添加一個k8s集群信息的model
class Cluster(models.Model): name = models.TextField() api = models.TextField() token = models.TextField() class Meta : db_table = "cluster" def __str__(self): return self.name這裏是k8s的連接通過api+token的方式進行連接，當然也可以用證書認證的方式
- name : 集群的名稱
- api : k8s集群的api 鏈接
- token ： k8s集群擁有admin權限的token
- cluster應用添加一個serializers.py文件
from rest_framework import serializers
from cluster.models import Cluster
class ClusterSerializer( serializers.ModelSerializer ):
class Meta:
model = Cluster
fields = ‘__all__‘- rest 框架根據這裏的配置對Cluster對象自動做序列化
- cluster 的view文件添加cluster的viewset
# /api/cluster/
class ClusterViewSet( viewsets.ModelViewSet ):
queryset = Cluster.objects.all()
serializer_class = ClusterSerializer
# permission_classes = (IsAuthenticated,)
parser_classes = (JSONParser,)
- rest 框架的parser有多種，這裏用的是jsonparser，需要再settings.py 中添加如下配置
REST_FRAMEWORK = {
‘DEFAULT_PARSER_CLASSES‘: (
‘rest_framework.parsers.JSONParser‘,
)
}
- 編輯admin.py,將cluster註冊到Django Admin後臺
from django.contrib import admin
from .models import Cluster
admin.site.register(Cluster)
- urls.py 中設置下路由
from cluster import views as cluster_views
router = DefaultRouter()
router.register(r‘cluster‘, cluster_views.ClusterViewSet)
urlpatterns = [
path( ‘admin/‘, admin.site.urls ),
path( ‘api/‘, include( router.urls ) ),
path(‘api-auth/‘, include(‘rest_framework.urls‘, namespace=‘rest_framework‘)),
]
-
測試下cluster的crud，以及rest api方式
- 運行django後，打開 http://127.0.0.1:8000/admin/cluster/cluster/
- 添加集群的信息
- 如果用rest 框架來看,就打開 http://127.0.0.1:8000/api/cluster/
-
加入kubernetes api,開始調試kubernetes
pip install kubernetes- cluster應用的view修改如下
from pprint import pprint
from django.shortcuts import get_object_or_404
from django.shortcuts import render
from kubernetes.client import Configuration, ApiClient, CoreV1Api
from rest_framework import viewsets
from rest_framework.decorators import action
from rest_framework.parsers import JSONParser
from cluster.models import Cluster
from .serializers import ClusterSerializer
def get_config(cluster):
‘‘‘
:param cluster: k8s集群的配置對象
:return: 返回一個config對象
‘‘‘
configuration = Configuration()
configuration.verify_ssl = False
configuration.host = cluster.api
configuration.api_key[‘authorization‘] = cluster.token
configuration.api_key_prefix[‘authorization‘] = ‘Bearer‘
return configuration
def get_clients(cluster):
‘‘‘
:param cluster: k8s集群對象
:return: 一個apiclient對象，一個coreV1Api對象
‘‘‘
api_client = ApiClient( get_config( cluster ) )
return api_client, CoreV1Api( api_client )
# /api/cluster/
class ClusterViewSet( viewsets.ModelViewSet ):
queryset = Cluster.objects.all()
serializer_class = ClusterSerializer
# permission_classes = (IsAuthenticated,)
parser_classes = (JSONParser,)
# /api/cluster/[pk]/list_service/
@action( detail=True, methods=[‘get‘] )
def list_service(self, request, pk=None):
cluster = get_object_or_404( Cluster, pk=pk )
api_client, core_v1_api = get_clients( cluster )
v1_service_list = core_v1_api.list_service_for_all_namespaces()
# pprint(v1_service_list)
result = {}
items = []
headers = [‘NAMESPACE‘, ‘NAME‘, ‘TYPE‘, ‘CLUSTER-IP‘, ‘SELF LINK‘]
for item in v1_service_list.items:
items.append( [item.metadata.namespace,
item.metadata.name,
item.spec.cluster_ip, item.spec.type, item.metadata.self_link
] )
result[‘items‘] = items
result[‘headers‘] = headers
result[‘caption‘] = "Services"
return render( request, "table.html", {‘result‘: result} )
# /api/cluster/[pk]/list_pod/
@action( detail=True, methods=[‘get‘] )
def list_pod(self, request, pk=None):
cluster = get_object_or_404( Cluster, pk=pk )
api_client, core_v1_api = get_clients( cluster )
v1_service_list = core_v1_api.list_pod_for_all_namespaces()
# pprint(v1_service_list)
result = {}
items = []
headers = [‘NAMESPACE‘, ‘NAME‘, ‘IP‘, ‘NODE‘]
for item in v1_service_list.items:
items.append( [
item.metadata.namespace,
item.metadata.name,
item.status.host_ip,
item.status.pod_ip,
] )
result[‘items‘] = items
result[‘headers‘] = headers
result[‘caption‘] = "Pods"
return render( request, "table.html", {‘result‘: result} )
因為這裏僅作了一個cluster測試，所以這裏將對k8s的連接也放在這裏，當如果正式的項目，應該放在一個獨立的文件，創建成連接池管理，再通過引用提供到這裏使用- 再次聲明，如果是這裏為了簡單，仍然用了django的template模式，當如果前後端分離開發，返回應該是序列化後的json
上面的list用到一個table.html模板，內容如下
<table class="table table-hover " id="service-table">
<caption>{{ result.caption }}</caption>
<thead>
<tr>
{% for item in result.headers %}
<th>{{ item }}</th>
{% endfor %}
</tr>
</thead>
<tbody>
{% for item in result.items %}
<tr>
{% for eny in item %}
<td>{{ eny }}</td>
{% endfor %}
</tr>
{% endfor %}
</tbody>
<tfoot>
<tr>
{% for item in result.headers %}
<th>{{ item }}</th>
{% endfor %}
</tr>
</tfoot>
</table>
-
項目中添加一個dashboard目錄，目錄下添加init.py，views.py文件
- 為了做當前頁面刷新，方便管理，所以多了一個dashboard來管理，views.py的內容如下
from django.shortcuts import render
from cluster.models import Cluster
def cluster_main(request):
result = {}
result[‘clusters‘] = Cluster.objects.all()
return render(request,‘main.html‘,{‘result‘:result})
- 在urls.py 中添加一條路由,最終內容如下
from django.contrib import admin
from django.urls import path
from django.conf.urls import include
from rest_framework.routers import DefaultRouter
from cluster import views as cluster_views
from dashboard import views as dashboard_views
router = DefaultRouter()
router.register(r‘cluster‘, cluster_views.ClusterViewSet)
urlpatterns = [
path( ‘admin/‘, admin.site.urls ),
path(‘dash/cluster‘,dashboard_views.cluster_main),
path( ‘api/‘, include( router.urls ) ),
path(‘api-auth/‘, include(‘rest_framework.urls‘, namespace=‘rest_framework‘)),
]
dashboard 中用了一個main.html模板，使用的是bootstrap+jquery+pace，實現當前頁面刷新:
{% load static %}
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>K8s 多集群管理測試</title>
<link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css">
<link rel="stylesheet"
href="https://cdn.jsdelivr.net/npm/[email protected]/src/messagebox.css">
<link rel="stylesheet" href="{% static ‘plugins/pace/pace.min.css‘ %}">
<script src="https://cdn.bootcss.com/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdn.bootcss.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<script src="http://mindmup.github.io/editable-table/mindmup-editabletable.js"></script>
<script src="https://cdn.jsdelivr.net/npm/[email protected]/src/messagebox.min.js"></script>
<script src="{% static ‘plugins/pace/pace.min.js‘ %}"></script>
</head>
<body>
<div class="container">
<nav class="navbar navbar-default" role="navigation">
<div class="container-fluid">
<div class="navbar-header">
<a class="navbar-brand" href="#">K8S Dashboard</a>
</div>
<form class="navbar-form navbar-left pull-right" role="search">
<div class="form-group">
<label for="k8s-api"></label>
<select class=" form-control" id="k8s-api">
<option value="#">選擇集群</option>
{% for cluster in result.clusters %}
<option value="{{ cluster.id }}">{{ cluster.name }}</option>
{% endfor %}
</select>
</div>
</form>
<ul class="nav navbar-nav navbar-right">
<li class="dropdown">
<a href="#" class="dropdown-toggle" data-toggle="dropdown">
選擇類型 <b class="caret"></b>
</a>
<ul class="dropdown-menu">
<li><a href="javascript:void(0);" onclick="load_table(‘/list_pod/‘)">Pod</a></li>
<li class="divider"></li>
<li><a href="javascript:void(0);" onclick="load_table(‘/list_service/‘)">Service</a></li>
</ul>
</li>
</ul>
</div>
</nav>
<div id="table-div"></div>
</div>
<script type="application/javascript">
$(document).ajaxStart(function () {
Pace.restart()
});
function load_table(url_method) {
console.log(url_method);
k8s_select = $("#k8s-api");
k8s_id = k8s_select.val();
if (k8s_id === "#") {
$.MessageBox({
buttonDone: "OK",
message: "<center>先選擇一個集群</center>",
queue: true,
speed: 200 ,
top: "25%" ,
});
return null;
}
url = ‘/api/cluster/‘ + k8s_id + url_method;
$.ajax({
url: url,
success: function (ex) {
console.log("success");
$(‘#table-div‘).html(ex);
},
error: function (ex) {
console.log(ex);
}
})
}
</script>
</body>
</html>
-
好了，完成這些後，終於做完了，現在可以測試下，完成的頁面就是上面的顯示圖片，下面來講講kubernetes api的使用
- k8s api 的主頁 https://github.com/kubernetes-client/python
- 主要的操作接口 ： https://github.com/kubernetes-client/python/blob/master/kubernetes/docs/CoreV1Api.md
如果想要連接k8s接口並操作，需要的步驟
- 創建一個Configuration，這是k8s的連接配置信息，這裏提供api接口跟token進行連接
configuration = Configuration() configuration.verify_ssl = False configuration.host = cluster.api configuration.api_key[‘authorization‘] = cluster.token configuration.api_key_prefix[‘authorization‘] = ‘Bearer‘-
根據config創建一個CoreV1Api，這個類下包含多個操作k8s的接口方法
api_client = ApiClient( configuration ) - 如果想要查看所有的service，利用接口list_service_for_all_namespaces
本文的源碼下載目錄:http://down.51cto.com/data/2450296
簡單開發k8s多集群後臺